As regards the Novice class, I don't think it was ever really intended to be a "terminal" license.
A bit of history....
Way back in the late 1920s, the old ABC system was created. All license classes required 10 wpm code and a somewhat-serious written test; the class A required a year experience and another written test.
In 1936 the code speed was increased to 13 wpm. The written tests were updated as FCC saw the need.
After WW2, there was seen a need for an easier way to get started in Amateur Radio. Learning code to 13 wpm and the theory test of the time was seen as a lot to learn, just to get started.
So, in 1951, the Novice license was created by FCC, with 5 wpm code, very simple 20-25 question test mostly on regulations, and very limited privileges - plus a 1 year, non-renewable term. The idea was that Novices would "learn by doing".
The Novice was an instant success and the number of US hams boomed all through the 1950s and into the 1960s.
The Technician, OTOH, was created as a special-purpose license with privileges on 220 and higher. It was NOT meant as a step between Novice and General, but as a special experiment-with-UHF license. But it never worked out that way.
The Tech, on the other hand was, and gave the same HF privileges as Novice plus full amateur privileges on 50MHz and above. I'm not sure why the FCC allowed Novice licenses to be renewed indefinitely, since the General theory exam, even when you had to write the answers yourself, wasn't all that hard and a Novice could sit for the test and upgrade to Technician. As a Tech you could still hang out in your Novice bands using Xtal control, if that's all you wanted to do, and there were some who did just that.
A bit more history:
One of the perceived problems with the Novice license was the number of dropouts. Not only was the license only good for a year but once someone had held any class of license they couldn't get a Novice.
So in 1967 the Novice term was increased to 2 years.
This still didn't seem to fix the dropout problem, so, in the early 1970s the rule was changed so that if someone held a Novice but then was unlicensed for a year, they could retest and get another Novice. Then the year wait was removed - pass the tests again and get another Novice. Finally in 1978 the Novice became renewable.
Meanwhile, the FCC kept pushing the idea that the Technician was NOT a step between Novice and General, but a special purpose license for experimenters - despite the reality of why most Techs were Techs. They finally gave up in 1977 and gave Technicians the same HF privileges as Novices.
The repeater boom of the 1970s-80s caused many new hams to bypass Novice and go straight to Technician. The Tech had privileges on 2 and 440, the two most popular repeater bands, while the Novice had neither.
Many became Techs for a while to get their code up from 5 to 13wpm, took that test, and upgraded to General...and were perfectly happy to stay there forever. Even after the FCC eliminated code requirements, they could have kept the Advanced class,but for some reason they didn't.
It was clear in 1998-1999 that FCC was serious about reducing the number of license classes, and reducing their administrative workload. Fewer license classes meant fewer test question pools, fewer upgrade applications, and eventually fewer regulations. In FCC's mind, the test requirement differences between Advanced and Extra didn't justify keeping both license classes.
Note that FCC created the Extra as part of the 1951 restructuring that gave us the Novice and Technician. The FCC of that time had been convinced that the old Class A/Advanced wasn't adequate for full privileges, and that the new Extra would replace it as the top license. They stopped issuing new Advanceds at the end of 1952 as part of the plan.
However, for some reason, in that same time period (late 1952), FCC completely reversed itself and gave full privileges to all US hams except Novices and Technicians, effective Feb 1953.
So for about 15 years, there were 6 US license classes but 4 of them had full privileges!
The Advanced stayed closed to new issues until some time in 1967, when, as part of "incentive licensing", FCC reopened it to new issues, seeing it as a step between General/Conditional and Extra.
In the years between the Great Giveaway of Feb 1953 and November 1968, when the restrictions of incentive licensing took effect, only a few thousand US hams got Extras, because there were no added privileges involved. IIRC, by the mid-1960s, less than 2% of US hams were Extras.
73 de Jim, N2EY
Novice 1967, age 13
Technician/Advanced, 1968, age 14
Extra, 1970, age 16
53 years licensed, 50 of them an Extra.
Current call sequentially issued 1977 - not a vanity.